Systems and methods for providing communications with an improved network frame structure architecture within wireless sensor networks

ABSTRACT

Systems and methods for providing communications with an improved network frame structure within wireless sensor networks are disclosed herein. In one embodiment, a system includes a hub having one or more processing units and RF circuitry for transmitting and receiving communications in a wireless network architecture. The system also includes a plurality of sensor nodes each having a wireless device with a transmitter and a receiver to enable bi-directional communications with the hub in the wireless network architecture. The one or more processing units of the hub are configured to execute instructions to cause a change from a first power mode of a receiver of a sensor node to a second power mode upon transmitting notifications to the sensor node during a repeated hub broadcasting time slot.

RELATED APPLICATIONS

This application is a continuation of U.S. Pat. No. 10,397,872, issuedon Aug. 27, 2019, entitled: SYSTEMS AND METHODS FOR PROVIDINGCOMMUNICATIONS WITH AN IMPROVED NETWORK FRAME STRUCTURE ARCHITECTUREWITHIN WIRELESS SENSOR NETWORKS, the contents of which are incorporatedby reference herein.

FIELD

Embodiments of the invention pertain to systems and methods forproviding communications with an improved network frame structurearchitecture within wireless sensor networks.

BACKGROUND

In the consumer electronics and computer industries, wireless sensornetworks have been studied for many years. In archetypal wireless sensornetworks, one or more sensors are implemented in conjunction with aradio to enable wireless collection of data from one or more sensornodes deployed within a network. Each sensor node may include one ormore sensors, and will include a radio and a power source for poweringthe operation of the sensor node. Prior wireless systems have difficultyin simultaneously achieving low power and low latency for networks witha large number of sensor nodes. Providing each sensor node a dedicatedtime slot would cause a wait time for a next slot to be too long.Providing each sensor node random access would cause collisions ifnumerous sensor nodes transmit at the same time.

SUMMARY

For one embodiment of the present invention, systems and methods forproviding communications within wireless sensor networks for improvednetwork frame structure for sensor nodes are disclosed herein. In oneembodiment, a system includes a hub having one or more processing unitsand RF circuitry for transmitting and receiving communications in awireless network architecture. The system also includes a plurality ofsensor nodes each having a wireless device with a transmitter and areceiver to enable bi-directional communications with the hub in thewireless network architecture. The one or more processing units of thehub are configured to execute instructions to cause a change from afirst power mode of a receiver of a sensor node to a second power modeupon transmitting notifications to the sensor node during a repeated hubbroadcasting time slot.

In one example, a sensor node for a wireless network architecturecomprises at least one sensor, a memory for storing instructions, andprocessing logic coupled to the memory and the at least one sensor. Theprocessing logic executes instructions for processing data received fromthe at least one sensor and for processing communications for the sensornod. Radio frequency (RF) circuitry is coupled to the processing logic.The RF circuitry includes transmitter and receiver functionality totransmit communications to a hub and to receive communications from thehub in the wireless network architecture. The processing logic isconfigured to execute instructions to change a first low power mode ofthe receiver functionality to a second power mode upon receivingcommunications having control or alarm information from the hub during arepeated hub broadcasting time slot with the control or alarminformation originating from the hub or from a group of sensor nodes.

Other features and advantages of embodiments of the present inventionwill be apparent from the accompanying drawings and from the detaileddescription that follows below.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention are illustrated by way of exampleand not limitation in the figures of the accompanying drawings, in whichlike references indicate similar elements, and in which:

FIG. 1 illustrates an exemplar system of wireless nodes having differentlength time slots for different types of communications for an improvednetwork frame structure in accordance with one embodiment.

FIG. 2 shows a system primarily having a tree network architecture thatis capable of mesh-like network functionality in which sensor nodes canhave different length time slots for different types of communicationsand suppression of notifications when appropriate for an improvednetwork frame structure in accordance with one embodiment.

FIG. 3 shows a system with an asymmetric tree and mesh networkarchitecture having multiple hubs in which each group of sensor nodes isassigned a time slot based on a pseudo random algorithm forcommunicating in accordance with one embodiment.

FIG. 4 illustrates a time line having different length time slots fordifferent types of communications for wireless nodes in a wirelessnetwork architecture in accordance with one embodiment.

FIG. 5 illustrates a method for determining different length time slotsfor different types of communications and suppression of notificationswhen appropriate for an improved network frame structure for wirelesssensor nodes in a wireless sensor network in accordance with oneembodiment.

FIG. 6 illustrates a method for scalable and energy efficient downlinkalarm delivery in accordance for wireless sensor nodes in a wirelesssensor network in accordance with one embodiment.

FIG. 7 illustrates a timeline having a scalable and energy efficient wayof downlink alarm delivery for wireless nodes in a wireless networkarchitecture in accordance with one embodiment.

FIG. 8 illustrates a method for operating sensor nodes in an energyefficient manner in a wireless sensor network in accordance with oneembodiment.

FIG. 9A shows an exemplary embodiment of a hub implemented as an overlay1500 for an electrical power outlet in accordance with one embodiment.

FIG. 9B shows an exemplary embodiment of an exploded view of a blockdiagram of a hub 1520 implemented as an overlay for an electrical poweroutlet in accordance with one embodiment.

FIG. 10A shows an exemplary embodiment of a hub implemented as a cardfor deployment in a computer system, appliance, or communication hub inaccordance with one embodiment.

FIG. 10B shows an exemplary embodiment of a block diagram of a hub 1664implemented as a card for deployment in a computer system, appliance, orcommunication hub in accordance with one embodiment.

FIG. 10C shows an exemplary embodiment of a hub implemented within anappliance (e.g., smart washing machine, smart refrigerator, smartthermostat, other smart appliances, etc.) in accordance with oneembodiment.

FIG. 10D shows an exemplary embodiment of an exploded view of a blockdiagram of a hub 1684 implemented within an appliance (e.g., smartwashing machine, smart refrigerator, smart thermostat, other smartappliances, etc.) in accordance with one embodiment.

FIG. 11 illustrates a block diagram of a sensor node in accordance withone embodiment.

FIG. 12 illustrates a block diagram of a system or appliance 1800 havinga hub in accordance with one embodiment.

DETAILED DESCRIPTION

Systems and methods for providing communications within wireless sensornetworks with improved network frame structure architecture aredisclosed herein. In one embodiment, a system includes a hub having oneor more processing units and RF circuitry for transmitting and receivingcommunications in a wireless network architecture. The system alsoincludes a plurality of sensor nodes each having a wireless device withtransmitter functionality and receiver functionality to enablebi-directional communications with the hub in the wireless networkarchitecture. The one or more processing units of the hub are configuredto execute instructions to cause a change from a first power mode of thereceiver functionality of a sensor node to a second power mode upontransmitting notifications to the sensor node during a repeated hubbroadcasting time slot with the notifications originating from the hubor from a different sensor node.

In one example, the notifications originate from the hub or from adifferent sensor node.

The hub can include RF circuitry that is operable during relevant timeperiods for receiving and transmitting communications to sensors nodesin wireless networks, particularly in indoor environments. For thepurpose of this, indoor environments are also assumed to includenear-indoor environments such as in the region around building and otherstructures, where similar issues (e.g., presence of nearby walls, etc.)may be present.

Wireless networks include a hub and devices that belong to one or moregroups of devices (e.g., sensor nodes). Devices are mostly sleeping tosave power while the hub always listens for any notifications from thedevices. Devices occasionally have to send notifications to the hub andother devices in their own group. Notifications usually appear inbursts. Some devices are more likely than others to have notificationssimultaneously. The number of devices is large enough to congest thewireless connection if random access is allowed during a burst. Deviceshaving random access would cause collisions if a large number of devicesend up transmitting at the same time. The number of devices is alsolarge enough that dedicated time slots for each device results in a longtime between the two slots of a device and thus low latency can not beguaranteed.

Low power and low latency are difficult to achieve simultaneously innetworks with a large number of devices (e.g., at least 5 devices, atleast 10 devices). A slotted frame structure like 802.15.4 TSCH haslarge slot length and this is only efficient for data transfer. Smallcontrol packets would only use a fraction of the slot making the networkthroughput very low for applications with a lot of control informationmixed with larger data packets.

The present design is targeted for applications in which it isbeneficial for a device to be able to communicate to or wake up certainsubset of devices from low power mode whenever needed.

The present design includes the following primary improvements: 1) mixof short uplink control slots, downlink forwarding slot and longer dataslots 2) control signal suppression enabled by grouping devices.

In one embodiment, an asymmetry in power availability may be exploitedto provide long range of communication in a wireless asymmetric networkarchitecture while maintaining long battery life for nodes that arepowered by a battery source. In an exemplary embodiment, a communicationrange of 20 meters between communicating nodes may be achieved whileproviding a long battery life (e.g., approximately 10 years, at leastten years) in battery operated nodes. This may be achieved byimplementing an energy aware networking protocol in accordance withembodiments of this invention. Specifically, a tree-like networkarchitecture having mesh based features may be used where long-lifebattery operated nodes are used on the terminal ends of the tree.

An exemplar tree-like network architecture has been described in U.S.patent application Ser. No. 14/607,045 filed on Jan. 29, 2015, U.S.patent application Ser. No. 14/607,047 filed on Jan. 29, 2015, U.S.patent application Ser. No. 14/607,048 filed on Jan. 29, 2015, and U.S.patent application Ser. No. 14/607,050 filed on Jan. 29, 2015, which areincorporated by reference in entirety herein.

A wireless sensor network is described for use in an indoor environmentincluding homes, apartments, office and commercial buildings, and nearbyexterior locations such as parking lots, walkways, and gardens. Thewireless sensor network may also be used in any type of building,structure, enclosure, vehicle, boat, etc. having a power source. Thesensor system provides good battery life for sensor nodes whilemaintaining long communication distances.

FIG. 1 illustrates an exemplar system of wireless nodes having differentlength time slots for different types of communications for an improvednetwork frame structure in accordance with one embodiment. The system100 primarily has a tree network architecture that is capable ofmesh-like network functionality in accordance with one embodiment. Thesystem 100 primarily has a tree network architecture for standardcommunications (e.g., (e.g., node identification information,notifications, sensor data, node status information, synchronizationinformation, localization information, other such information for thewireless sensor network, time of flight (TOF) communications, etc.). Thesystem 100 includes a hub 110 having a wireless control device 111, asensor node 120 having a wireless device 121, a sensor node 124 having awireless device 125, a sensor node 128 having a wireless device 129, asensor node 130 having a wireless device 131, and a sensor node 132having a wireless device 133. Additional hubs that are not shown cancommunicate with the hub 110 or other hubs. Each hub communicatesbi-directionally with the sensor nodes 120, 124, 128, 130, and 132. Thehubs are also designed to communicate bi-directionally with otherdevices (e.g., client device, mobile device, tablet device, computingdevice, smart appliance, smart TV, etc.).

In one embodiment, the control device 111 of the hub 110 is configuredto execute instructions to determine different length time slots fordifferent types of communications between the hub and the sensor nodes(e.g., nodes 120, 124, 128, 130, 132). For example, the control device111 can be configured to determine shorter uplink control time slots,downlink forwarding time slots, and longer data time slots. The hub orsensor node is also configured for suppression of notifications whenappropriate due to grouping of sensor nodes.

A sensor node is a terminal node if it only has upstream communicationswith a higher level hub or node and no downstream communications withanother hub or node. Each wireless device includes RF circuitry with atransmitter and a receiver (or transceiver) to enable bi-directionalcommunications with hubs or other sensor nodes.

FIG. 2 shows a system primarily having a tree network architecture thatis capable of mesh-like network functionality in which sensor nodes canhave different length time slots for different types of communicationsand suppression of notifications when appropriate for an improvednetwork frame structure in accordance with one embodiment. The system250 may establish a mesh-like network architecture for determininglocations sensor nodes based on a threshold criteria (e.g., movement ofat least one node by a certain distance, a change in path length betweena node and the hub by a certain distance) being triggered. The system250 includes a hub 210, a first group 295 of nodes 220, 224, 228, 230,232 and a second group 296 of nodes 270, 280, and 290. The sensor nodescan be assigned into different groups. In another example, the group 296is split into a first subgroup of nodes 220 and 224 and a secondsubgroup of nodes 228, 230, and 232. In one example, each group (orsubgroup) is assigned a pseudo random time slot for communicating withother nodes or hubs.

The hub 210 includes the wireless device 211, the sensor node 220includes the wireless device 221, the sensor node 224 includes thewireless device 225, the sensor node 228 includes the wireless device229, the sensor node 230 includes the wireless device 231, the sensornode 232 includes the wireless device 233, the sensor node 270 includesthe wireless device 271, the sensor node 280 includes the wirelessdevice 281, and the sensor node 290 includes the wireless device 291.Additional hubs that are not shown can communicate with the hub 210 orother hubs. The hub 210 communicates bi-directionally with the sensornodes.

These communications include bi-directional communications 240-244, 272,282, and 292 in the wireless asymmetric network architecture. The sensornodes communicate bi-directionally with each other based oncommunications 261-266, 273, and 283 to provide the mesh-likefunctionality for different applications including determining locationsof the hub and sensor nodes.

In one embodiment, the control device 211 of the hub 210 is configuredto execute instructions to determine different length time slots fordifferent types of communications between the hub and the sensor nodes.For example, the control device 211 can be configured to determineshorter uplink control time slots, downlink forwarding time slots, andlonger data time slots. The hub or sensor node is also configured forsuppression of notifications when appropriate due to grouping of sensornodes.

FIG. 3 shows a system with an asymmetric tree and mesh networkarchitecture having multiple hubs in which each group of sensor nodes isassigned a time slot based on a pseudo random algorithm forcommunicating in accordance with one embodiment. The system 700 includesa central hub 710 having a wireless control device 711, hub 720 having awireless control device 721, hub 782 having a wireless control device783, and additional hubs including hub n having a wireless controldevice n. Additional hubs which are not shown can communicate with thecentral hub 710, other hubs, or can be an additional central hub. Eachhub communicates bi-directionally with other hubs and one or more sensornodes. The hubs are also designed to communicate bi-directionally withother devices including device 780 (e.g., client device, mobile device,tablet device, computing device, smart appliance, smart TV, etc.).

The sensor nodes 730, 740, 750, 760, 770, 788, 792, n, and n+1 (orterminal nodes) each include a wireless device 731, 741, 751, 761, 771,789, 793, 758, and 753, respectively. A sensor node is a terminal nodeif it only has upstream communications with a higher level hub or nodeand no downstream communications with another hub or node. Each wirelessdevice includes RF circuitry with a transmitter and a receiver (ortransceiver) to enable bi-directional communications with hubs or othersensor nodes.

In one embodiment, the central hub 710 communicates with hubs 720, 782,hub n, device 780, and nodes 760 and 770. These communications includecommunications 722, 724, 774, 772, 764, 762, 781, 784, 786, 714, and 712in the wireless asymmetric network architecture. The central hub havingthe wireless control device 711 is configured to send communications toother hubs and to receive communications from the other hubs forcontrolling and monitoring the wireless asymmetric network architectureincluding assigning groups of nodes and assigning time slots based on apseudo random algorithm with different length time slots for differenttypes of communications.

The hub 720 communicates with central hub 710 and also sensors nodes730, 740, and 750. The communications with these sensor nodes includecommunications 732, 734, 742, 744, 752, and 754. For example, from theperspective of the hub 720, the communication 732 is received by the huband the communication 734 is transmitted to the sensor node. From theperspective of the sensor node 730, the communication 732 is transmittedto the hub 720 and the communication 734 is received from the hub.

In one embodiment, a central hub (or other hubs) assign nodes 760 and770 to a group 716, nodes 730, 740, and 750 to a group 715, nodes 788and 792 to a group 717, and nodes n and n+1 to a group n. In anotherexample, groups 716 and 715 are combined into a single group.

A wireless control device of the central hub, alone or in combinationwith other hubs, is configured to execute instructions to determinedifferent length time slots for different types of communicationsbetween the hub(s) and the sensor nodes. For example, a hub can beconfigured to determine shorter uplink control time slots, downlinkforwarding time slots, and longer data time slots. The hub or sensornode is also configured for suppression of notifications whenappropriate (e.g., when certain notifications are not needed ordesired).

By using the architectures illustrated in FIGS. 1-3, nodes requiringlong battery life minimize the energy expended on communication andhigher level nodes in the tree hierarchy are implemented using availableenergy sources or may alternatively use batteries offering highercapacities or delivering shorter battery life. To facilitate achievementof long battery life on the battery-operated terminal nodes,communication between those nodes and their upper level counterparts(hereafter referred to as lowest-level hubs) may be established suchthat minimal transmit and receive traffic occurs between thelowest-level hubs and the terminal nodes.

In one embodiment, the nodes spend most of their time (e.g., more than90% of their time, more than 95% of their time, approximately 98% ormore than 99% of their time) in a low-energy non-communicative state.When the node wakes up and enters a communicative state, the nodes areoperable to transmit data to the lowest-level hubs. This data mayinclude node identification information, sensor data, node statusinformation, synchronization information, localization information andother such information for the wireless sensor network.

In one example, in order to save power, sensor nodes configured in a lowpower mode (e.g., sleeping state) only wake up in a higher power modeand check if a downlink forwarding slot has a communication signal init. A hub that is typically receiving uplink traffic uses this slot toforward any short group messages it has received. A group identifier inthe message tells the receiving sensor nodes which group is supposed toreact or stay awake after receiving this message. A sensor node thatneeds to send a group message uses one of the uplink slots in a randomlydetermined manner. A random slot can be calculated so that there is verylittle chance (or none at all) for a collision within one group. Thiswould be beneficial in applications where groups can be formed fromsensor nodes that are more likely to transmit control information at thesame time. For example, a network that senses space occupancy includesgroups of sensor nodes. Each sensor node within a first group is morelikely to transmit control information at approximately the same timewhen occupancy is detected in contrast to a second group of sensor nodesthat is not currently sensing occupancy.

In applications in which the main purpose of the control message is towake up a group of devices and in which the group is more likely to haveseveral devices to wake up at the same time it is not necessary for alldevices (e.g., sensor nodes) to transmit the wake up command. Thepresent design includes the concept of signal suppression to reducecongestion of the wireless network. When several devices in a group aretrying to send control information these devices use pseudo randomlyallocated time slots. While waiting for their transmit time slot thesedevice have operable receive modes to detect any other transmission fromthe same group. If a transmission from another device of the group isdetected, then the device cancels its own future transmission to reducenetwork congestion for the wireless network. If a control packet of anotification ends up being transmitted by one of the devices in a group,then the confirmation of the successful reception of this control packetor another control packet for any device in this group may be detectedin a subsequent downlink broadcast slot. If confirmation is detected,then all devices in the group that receive the confirmation willsuppress their future transmissions. Otherwise the device keep repeatingtransmissions with control packets until the confirmation is detectedfor at least one transmission.

FIG. 4 illustrates a time line having different length time slots fordifferent types of communications for wireless nodes in a wirelessnetwork architecture in accordance with one embodiment. A broadcastbeacon signal 402-406 is periodically repeated on a time line 450. Thebroadcast beacon signal may include 1 byte field x indicating to othersystems that this is a beacon frame followed by field y that can includeinformation where the frame related information 441 and 442 can be foundinside the beacon info 440. Frames like 422 are time slots where hub andnodes can communicate without other systems interfering. During theframes, data, acknowledgment, notifications, beacon, or MAC commandpackets can be sent.

Defining the frames using a known protocol in the beginning of thebeacon before a proprietary content prevents other system fromtransmitting during the time periods of the guaranteed time slots. Inone example, no other system (e.g., IEEE 802.15.4 systems) will transmitduring a time period 422 (or other similar periodic time periods) basedon including the frame information 441 and 442 at the beginning of everybeacon. The frame order field 442 includes information about the lengthof the frame and the beacon order field 441 includes the informationabout the time between two frames.

Additional details of a network frame architecture has been described inU.S. patent application Ser. No. 14/925,889 filed on Oct. 28, 2015,which is incorporated by reference in entirety herein.

In one example, a hub utilizes a pseudo random algorithm to determinetime slots 411-420 for a first group of sensor nodes. The pseudo randomalgorithm can define a different length time slot for different types ofcommunications. In one example, devices (e.g., sensor nodes) in a firstgroup have operable transmitters for transmitting notifications (e.g.,control information, alarm information) during time slot signals 411,412, and 415-420. Devices (e.g., sensor nodes) in the first group haveoperable transmitters for transmitting data communications during longertime slot signals 413-414. Each time slot signal can be partitioned intoshorter time slots for multiple sensor nodes.

FIG. 5 illustrates a method for determining different length time slotsfor different types of communications and suppression of notificationswhen appropriate for an improved network frame structure for wirelesssensor nodes in a wireless sensor network in accordance with oneembodiment. The operations of method 500 may be executed by a wirelessdevice, a wireless control device of a hub (e.g., an apparatus), orsystem, which includes processing circuitry or processing logic. Theprocessing logic may include hardware (circuitry, dedicated logic,etc.), software (such as is run on a general purpose computer system ora dedicated machine or a device), or a combination of both. In oneembodiment, an anchor node, hub, or a wireless device performs theoperations of method 500.

A wireless network architecture having a plurality of wireless nodes andat least one hub is initialized at operation 501. Initialization mayinclude determining locations of each of the plurality of wirelessnodes.

At operation 502, processing logic of a hub determines groups ofwireless sensor nodes, a group identifier for each group, a first deviceidentifier for each sensor node, and a second shortened or reduceddevice identifier for each sensor node. At operation 504, the processinglogic of the hub determines a first length of time slots (e.g., 30units, approximately 300 microseconds, less than 500 microseconds, etc.)for notifications within the wireless network and a second differentlength of time slots (e.g., 1000 units, approximately 10 milliseconds,at least 1 millisecond, etc.) for data communications. In one example,wireless network is optimized for notifications with first length oftime slots (e.g., 30 units, approximately 300 microseconds, less than500 microseconds, etc.) for a first time period and the second differentlength of time slots (e.g., 1000 units, approximately 10 milliseconds,at least 1 millisecond, etc.) for data communications for a second timeperiod. The hub can switch between the first and second length of timeslots depending on a particular application for the wireless sensornetwork.

At operation 506, the processing logic of the hub determines a hashfunction for each sensor node based on the second device identifier foreach sensor node. The hub can assign the shortened device identifier ina way such that the hash function that is based on the short deviceidentifier can effectively spread the uplink packets across allavailable time slots.

At operation 508, the processing logic of the hub executes a pseudorandom algorithm to randomly assign time slots to each sensor node basedon at least the hash function, second device identifiers, time, andgroup identifiers. A pseudo random time slot is designed based on sensornodes in a group being less likely to have a same time slot compared toother sensor nodes in the same group while sensor nodes in differentgroups being more likely to occupy a same time slot.

In one example, a triggering event sensed by the wireless sensornetwork, causes an alarm signal to be generated and this alarm signalshould be reliably delivered, which requires a retransmission mechanism.An alarm signal can be transmitted from multiple sensor nodes at thesame time, and thus a large number of uplink alarm micro time slots areneeded. A retransmission mechanism that relies on unicast can increasethe micro time slot size, which limits the number of uplink alarm microtime slots.

In one example, an alarm signal is a per constellation (e.g., per group)control packet. As the number of constellation increases, a TDMA systemwill require a larger number of downlink alarm time slots, which is notscalable. Further since multiple downlink alarm time slots forces thesensor nodes to have active receive modes for more time slots to receivealarm packets, this causes an increase in the active duration of a RFmodule of the sensor node.

Therefore, the present design provides a scalable and energy efficientway of downlink alarm delivery. FIG. 6 illustrates a method for scalableand energy efficient downlink alarm delivery in accordance for wirelesssensor nodes in a wireless sensor network in accordance with oneembodiment. The operations of method 600 may be executed by a wirelessdevice, a wireless control device of a hub (e.g., an apparatus), orsystem, which includes processing circuitry or processing logic. Theprocessing logic may include hardware (circuitry, dedicated logic,etc.), software (such as is run on a general purpose computer system ora dedicated machine or a device), or a combination of both. In oneembodiment, a node, hub, or a wireless device performs the operations ofmethod 600.

At operation 602, a hub receives a communication with alarm informationfrom at least one group of sensor nodes. At operation 604, the hubprovides a target alarm delay by waiting to receive additionalcommunications with alarm information (e.g., uplink alarms) fromadditional sensor nodes and potentially different groups of sensor nodesduring a certain period.

Then, at operation 606, the hub identifies the unique alarms from thegroups of sensor nodes (e.g., constellations) and combines multiplealarm information for different groups of sensor nodes (e.g.,constellations) into a communication having an alarm packet. In oneexample, a first group of sensor nodes transmits first alarm informationto the hub and a second group of sensor nodes transmits second alarminformation to the hub. At operation 608, the hub assigns a downlinkalarm time slot that each sensor node needs to receive while in anactive receive mode. The hub can assign the downlink alarm time slot tothe sensor node by using a hash function (e.g., y=f (constellation id)).

At operation 610, the hub is configured to execute instructions to causea change from a first power mode of a receiver of at least one sensornode to a second power mode upon transmitting notifications to the atleast one sensor node during a repeated hub broadcasting time slot withthe notifications originating from the hub or from a different sensornode. The sensor nodes may need to have a second power mode (e.g., anactive receive mode).

FIG. 7 illustrates a timeline having a scalable and energy efficient wayof downlink alarm delivery for wireless nodes in a wireless networkarchitecture in accordance with one embodiment. A broadcast beaconsignal 702 is periodically repeated on a time line 700. The broadcastbeacon signal may include 1 byte field indicating to other systems thatthis is a beacon frame followed by other fields that can include otherinformation. An aggregated alarm signal 704 can include alarminformation from multiple sensor nodes and multiple groups of sensors.The hub removes device identifiers for the alarm information and addsgroup identifiers to the alarm information. The sensors nodes canmonitor the alarm information of the aggregated alarm information toidentify a relevant group identifier for a particular sensor node. Thesignal 706 can include additional aggregated alarm information for adifferent group identifier or the signal 706 can be a different type ofcontrol packet. For example, aggregating multiple information can beused for other control packets such as capturing images with the sensornodes, obtaining images and deleting images, etc.

In one example, the aggregated alarm signal 704 includes alarminformation for groups 1-4 and aggregate alarm signal 706 includes alarminformation for groups 5-8.

The present design provides an alarm retransmission mechanism byutilizing a detected forwarded alarm signal as an acknowledgement. Aftersending a broadcast alarm signal, a sensor node that transmits the alarmsignal waits for a next alarm slot to check if the transmitted alarmsignal has been forwarded or not (e.g., forwarded by a hub). If thesensor node can receive the forwarded alarm signal, then this indicatesthat the hub received the alarm signal, which does not trigger aretransmission of the alarm signal. Otherwise, the sensor noderetransmits the alarm signal regarding such case as no alarm deliveryfrom the sensor node to the hub.

In one example, a sensor node detects a triggering event that causes thesensor node to generate and transmit an alarm signal during a nextrandomly determined time slot. The hub receives the alarm signal anddetermines an action (e.g., repeating the alarm signal which causes allnodes to wake, causing an alarm signal to be sent to a home owner,police station, fire station, ambulance, etc.) based on receiving thealarm signal. Upon waking other sensor nodes, the hub may receiveadditional communications from other sensors. The hub can then determinean appropriate action based on the additional communications. Forexample, all sensors after receiving a wake signal from the hub maycapture images and transmit the images to the hub for analysis.

In one example, retransmission of data is based on whether anacknowledgement communication is detected. To reduce length of timeslot, carrier sensing and backoff slot inside time slot are notappropriate.

Therefore, the present design reduces the chance of collision duringuplink packet transmission from multiple nodes by spreading out theuplink packets from sensor nodes to hub(s) across all available timeslots. The present design utilizes randomness for time slot selection.

FIG. 8 illustrates a method for operating sensor nodes in an energyefficient manner in a wireless sensor network in accordance with oneembodiment. The operations of method 800 may be executed by a wirelessdevice, a wireless control device of a hub (e.g., an apparatus), orsystem, which includes processing circuitry or processing logic. Theprocessing logic may include hardware (circuitry, dedicated logic,etc.), software (such as is run on a general purpose computer system ora dedicated machine or a device), or a combination of both. In oneembodiment, a sensor node or wireless device performs the operations ofmethod 800.

At operation 802, processing logic of a sensor node is configured tochange a first low power mode of a receiver functionality of the sensornode to a second power mode upon receiving communications having controlor alarm information or alarm information from a hub during a repeatedhub broadcasting time slot with the control or alarm informationoriginating from the hub or from a group of sensor nodes. The receiverfunctionality of the sensor node is configured at a minimum level ofpower to listen to broadcast messages (e.g., only operable receiverfunctionality) during the first power mode and operable during thesecond power mode at any level above the minimum level of powerincluding having operable transmitter functionality.

At operation 808, the processing logic of the sensor node is configuredto execute instructions to determine a group identifier for the receivedcommunications, to determine a group identifier for the sensor node, andto cancel transmission of a communication from the sensor node if thegroup identifier for the received communications matches the groupidentifier for the sensor node to reduce congestion within the wirelessnetwork.

In one example, a group of sensor nodes is formed to increase alikelihood that the sensor nodes of the group will transmitcommunications at approximately the same time or close in time.

At operation 810, the processing logic of the sensor node is configuredto execute instructions to transmit a communication, to verifysuccessful reception of any communication by checking a next hubbroadcast slot for notice forwarding, and to retransmit thecommunication with at least one modified parameter of a pseudo randomfunction when successful reception is not verified.

The communication between hubs and nodes as discussed herein may beachieved using a variety of means, including but not limited to directwireless communication using radio frequencies, Powerline communicationachieved by modulating signals onto the electrical wiring within thehouse, apartment, commercial building, etc., WiFi communication usingsuch standard WiFi communication protocols as 802.11a, 802.11b, 802.11n,802.11ac, and other such Wifi Communication protocols as would beapparent to one of ordinary skill in the art, cellular communicationsuch as GPRS, EDGE, 3G, HSPDA, LTE, and other cellular communicationprotocols as would be apparent to one of ordinary skill in the art,Bluetooth communication, communication using well-known wireless sensornetwork protocols such as Zigbee, and other wire-based or wirelesscommunication schemes as would be apparent to one of ordinary skill inthe art.

The implementation of the radio-frequency communication between theterminal nodes and the hubs may be implemented in a variety of waysincluding narrow-band, channel overlapping, channel stepping,multi-channel wide band, and ultra-wide band communications.

The hubs may be physically implemented in numerous ways in accordancewith embodiments of the invention. FIG. 9A shows an exemplary embodimentof a hub implemented as an overlay 1500 for an electrical power outletin accordance with one embodiment. The overlay 1500 (e.g., faceplate)includes a hub 1510 and a connection 1512 (e.g., communication link,signal line, electrical connection, etc.) that couples the hub to theelectrical outlet 1502. Alternatively (or additionally), the hub iscoupled to outlet 1504. The overlay 1500 covers or encloses theelectrical outlets 1502 and 1504 for safety and aesthetic purposes.

FIG. 9B shows an exemplary embodiment of an exploded view of a blockdiagram of a hub 1520 implemented as an overlay for an electrical poweroutlet in accordance with one embodiment. The hub 1520 includes a powersupply rectifier 1530 that converts alternating current (AC), whichperiodically reverses direction, to direct current (DC) which flows inonly one direction. The power supply rectifier 1530 receives AC from theoutlet 1502 via connection 1512 (e.g., communication link, signal line,electrical connection, etc.) and converts the AC into DC for supplyingpower to a controller circuit 1540 via a connection 1532 (e.g.,communication link, signal line, electrical connection, etc.) and forsupplying power to RF circuitry 1550 via a connection 1534 (e.g.,communication link, signal line, electrical connection, etc.). Thecontroller circuit 1540 includes memory 1542 or is coupled to memorythat stores instructions which are executed by processing logic 1544(e.g., one or more processing units) of the controller circuit 1540 forcontrolling operations of the hub for forming, monitoring, andperforming localization of the wireless asymmetrical network asdiscussed herein. The RF circuitry 1550 may include a transceiver orseparate transmitter 1554 and receiver 1556 functionality for sendingand receiving bi-directional communications via antenna(s) 1552 with thewireless sensor nodes. The RF circuitry 1550 communicatesbi-directionally with the controller circuit 1540 via a connection 1534(e.g., communication link, signal line, electrical connection, etc.).The hub 1520 can be a wireless control device 1520 or the controllercircuit 1540, RF circuitry 1550, and antenna(s) 1552 in combination mayform the wireless control device as discussed herein.

FIG. 10A shows an exemplary embodiment of a hub implemented as a cardfor deployment in a computer system, appliance, or communication hub inaccordance with one embodiment. The card 1662 can be inserted into thesystem 1660 (e.g., computer system, appliance, or communication hub) asindicated by arrow 1663.

FIG. 10B shows an exemplary embodiment of a block diagram of a hub 1664implemented as a card for deployment in a computer system, appliance, orcommunication hub in accordance with one embodiment. The hub 1664includes a power supply 1666 that provides power (e.g., DC power supply)to a controller circuit 1668 via a connection 1674 (e.g., communicationlink, signal line, electrical connection, etc.) and provides power to RFcircuitry 1670 via a connection 1676 (e.g., communication link, signalline, electrical connection, etc.). The controller circuit 1668 includesmemory 1661 or is coupled to memory that stores instructions which areexecuted by processing logic 1663 (e.g., one or more processing units)of the controller circuit 1668 for controlling operations of the hub forforming, monitoring, and communicating within the wireless asymmetricalnetwork as discussed herein. The RF circuitry 1670 may include atransceiver or separate transmitter 1675 and receiver 1677 functionalityfor sending and receiving bi-directional communications via antenna(s)1678 with the wireless sensor nodes. The RF circuitry 1670 communicatesbi-directionally with the controller circuit 1668 via a connection 1672(e.g., communication link, signal line, electrical connection, etc.).The hub 1664 can be a wireless control device 1664 or the controllercircuit 1668, RF circuitry 1670, and antenna(s) 1678 in combination mayform the wireless control device as discussed herein.

FIG. 10C shows an exemplary embodiment of a hub implemented within anappliance (e.g., smart washing machine, smart refrigerator, smartthermostat, other smart appliances, etc.) in accordance with oneembodiment. The appliance 1680 (e.g., smart washing machine) includes ahub 1682.

FIG. 10D shows an exemplary embodiment of an exploded view of a blockdiagram of a hub 1684 implemented within an appliance (e.g., smartwashing machine, smart refrigerator, smart thermostat, other smartappliances, etc.) in accordance with one embodiment. The hub includes apower supply 1686 that provides power (e.g., DC power supply) to acontroller circuit 1690 via a connection 1696 (e.g., communication link,signal line, electrical connection, etc.) and provides power to RFcircuitry 1692 via a connection 1698 (e.g., communication link, signalline, electrical connection, etc.). The controller circuit 1690 includesmemory 1691 or is coupled to memory that stores instructions which areexecuted by processing logic 1688 (e.g., one or more processing units)of the controller circuit 1690 for controlling operations of the hub forforming, monitoring, and performing localization of the wirelessasymmetrical network as discussed herein. The RF circuitry 1692 mayinclude a transceiver or separate transmitter 1694 and receiver 1695functionality for sending and receiving bi-directional communicationsvia antenna(s) 1699 with the wireless sensor nodes. The RF circuitry1692 communicates bi-directionally with the controller circuit 1690 viaa connection 1689 (e.g., communication link, signal line, electricalconnection, etc.). The hub 1684 can be a wireless control device 1684 orthe controller circuit 1690, RF circuitry 1692, and antenna(s) 1699 incombination may form the wireless control device as discussed herein.

In one embodiment, an apparatus (e.g., hub) for providing a wirelessasymmetric network architecture includes a memory for storinginstructions, processing logic (e.g., one or more processing units,processing logic 1544, processing logic 1663, processing logic 1688,processing logic 1763, processing logic 1888) of the hub to executeinstructions to establish and control communications in a wirelessasymmetric network architecture, and radio frequency (RF) circuitry(e.g., RF circuitry 1550, RF circuitry 1670, RF circuity 1692, RFcircuitry 1890) including multiple antennas (e.g., antenna(s) 1552,antenna(s) 1678, antenna(s) 1699, antennas 1311, 1312, and 1313, etc.)to transmit and receive communications in the wireless asymmetricnetwork architecture. The RF circuitry and multiple antennas to transmitcommunications to a plurality of sensor nodes (e.g., node 1, node 2)each having a wireless device with a transmitter and a receiver (ortransmitter and receiver functionality of a transceiver) to enablebi-directional communications with the RF circuitry of the apparatus inthe wireless asymmetric network architecture. The one or more processingunits are configured to execute instructions to receive at least onecommunication with alarm information from at least one group of sensornodes and to provide a target alarm delay by waiting to receiveadditional communications with alarm information from additional sensornodes and potentially different groups of sensor nodes during a certainperiod.

In one example, the one or more processing units of the apparatus areconfigured to execute instructions to identify unique alarms from the atleast one communications received from the at least one group of sensornodes.

In another example, the one or more processing units of the apparatusare configured to execute instructions to combine multiple alarminformation of the unique alarms for different groups of sensor nodesinto a communication having an alarm packet.

In another example, the one or more processing units of the apparatusare configured to execute instructions to receive a first plurality ofcommunications having first alarm information from a first group ofsensor nodes and to receive a second plurality of communications havingsecond alarm information from a second group of sensor nodes.

In another example, the one or more processing units of the apparatusare configured to execute instructions to assign a downlink alarm timeslot for the alarm packet to be transmitted to the sensor nodes by usinga hash function.

In another example, the one or more processing units of the apparatusare configured to execute instructions to cause a change from a firstpower mode of a receiver of a sensor node to a second power mode upontransmitting the alarm packet with the alarm information to the sensornode during a repeated hub broadcasting time slot.

Various batteries could be used in the wireless sensor nodes, includinglithium-based chemistries such as Lithium Ion, Lithium Thionyl Chloride,Lithium Manganese Oxide, Lithium Polymer, Lithium Phosphate, and othersuch chemistries as would be apparent to one of ordinary skill in theart. Additional chemistries that could be used include Nickel metalhydride, standard alkaline battery chemistries, Silver Zinc and Zinc Airbattery chemistries, standard Carbon Zinc battery chemistries, lead Acidbattery chemistries, or any other chemistry as would be obvious to oneof ordinary skill in the art.

The present invention also relates to an apparatus for performing theoperations described herein. This apparatus may be specially constructedfor the required purposes, or it may comprise a general purpose computerselectively activated or reconfigured by a computer program stored inthe computer. Such a computer program may be stored in a computerreadable storage medium, such as, but not limited to, any type of diskincluding floppy disks, optical disks, CD-ROMs, and magnetic-opticaldisks, read-only memories (ROMs), random access memories (RAMs), EPROMs,EEPROMs, magnetic or optical cards, or any type of media suitable forstoring electronic instructions.

The algorithms and displays presented herein are not inherently relatedto any particular computer or other apparatus. Various general purposesystems may be used with programs in accordance with the teachingsherein, or it may prove convenient to construct a more specializedapparatus to perform the required method operations.

FIG. 11 illustrates a block diagram of a sensor node in accordance withone embodiment. The sensor node 1700 includes a power source 1710 (e.g.,energy source, battery source, primary cell, rechargeable cell, etc.)that provides power (e.g., DC power supply) to a controller circuit 1720via a connection 1774 (e.g., communication link, signal line, electricalconnection, etc.), provides power to RF circuitry 1770 via a connection1776 (e.g., communication link, signal line, electrical connection,etc.), and provides power to sensing circuitry 1740 via a connection1746 (e.g., communication link, signal line, electrical connection,etc.). The controller circuit 1720 includes memory 1761 or is coupled tomemory that stores instructions which are executed by processing logic1763 (e.g., one or more processing units) of the controller circuit 1720for controlling operations of the sensor node for forming and monitoringthe wireless asymmetrical network as discussed herein. The RF circuitry1770 (e.g., communication circuitry) may include a transceiver orseparate transmitter 1775 and receiver 1777 functionality for sendingand receiving bi-directional communications via antenna(s) 1778 with thehub(s) and optional wireless sensor nodes. The RF circuitry 1770communicates bi-directionally with the controller circuit 1720 via aconnection 1772 (e.g., electrical connection). The sensing circuitry1740 includes various types of sensing circuitry and sensor(s) includingimage sensor(s) and circuitry 1742, moisture sensor(s) and circuitry1743, temperature sensor(s) and circuitry, humidity sensor(s) andcircuitry, air quality sensor(s) and circuitry, light sensor(s) andcircuitry, motion sensor(s) and circuitry 1744, audio sensor(s) andcircuitry 1745, magnetic sensor(s) and circuitry 1746, and sensor(s) andcircuitry n, etc.

In one embodiment, a sensor node for a wireless network architectureincludes at least one sensor, a memory for storing instructions,processing logic coupled to the memory and the at least one sensor. Theprocessing logic executes instructions for processing data received fromthe at least one sensor and for processing communications for the sensornode. The sensor node includes radio frequency (RF) circuitry that iscoupled to the processing logic. The RF circuitry includes transmitterand receiver functionality to transmit communications to a hub and toreceive communications from the hub in the wireless networkarchitecture. The processing logic is configured to execute instructionsto processing logic is configured to execute instructions to change afirst low power mode of the receiver functionality to a second powermode upon receiving communications having control or alarm informationfrom the hub during a repeated hub broadcasting time slot with thecontrol or alarm information originating from the hub or from a group ofsensor nodes.

In one example, the control or alarm information originates from the hubor from a group of sensor nodes.

In another example, the receiver functionality of the sensor node isconfigured to be at a minimum level of power to listen to broadcastmessages (e.g., only have operable receiver functionality) during thefirst power mode and operable during the second power mode at any levelabove the minimum level of power including having operable transmitterfunctionality.

In another example, the processing logic is configured to executeinstructions to determine a group identifier for the receivedcommunications, to determine a group identifier for the sensor node, andto cancel transmission of a communication from the sensor node if thegroup identifier for the received communications matches the groupidentifier for the sensor node to reduce congestion within the wirelessnetwork.

In another example, the group of sensor nodes is formed to increase alikelihood that the sensor nodes of the group will transmitcommunications at approximately the same time or close in time.

In another example, the sensor node operates with a battery source.

In another example, the processing logic is configured to executeinstructions to transmit a communication, to verify successful receptionof any communication by checking a next hub broadcast slot for noticeforwarding, and to retransmit the communication with at least onemodified parameter of a pseudo random function when successful receptionis not verified.

In one example, the sensor node is configured to execute instructions todetect at least one of energy of the transmission and a preamble of thetransmission to ascertain the transmission without consuming power toprocess data of the transmission.

FIG. 12 illustrates a block diagram of a system 1800 having a hub inaccordance with one embodiment. The system 1800 includes or isintegrated with a hub 1882 or central hub of a wireless asymmetricnetwork architecture. The system 1800 (e.g., computing device, smart TV,smart appliance, communication system, etc.) may communicate with anytype of wireless device (e.g., cellular phone, wireless phone, tablet,computing device, smart TV, smart appliance, etc.) for sending andreceiving wireless communications. The system 1800 includes a processingsystem 1810 that includes a controller 1820 and processing units 1814.The processing system 1810 communicates with the hub 1882, anInput/Output (I/O) unit 1830, radio frequency (RF) circuitry 1870, audiocircuitry 1860, an optics device 1880 for capturing one or more imagesor video, an optional motion unit 1844 (e.g., an accelerometer,gyroscope, etc.) for determining motion data (e.g., in three dimensions)for the system 1800, a power management system 1840, andmachine-accessible non-transitory medium 1850 via one or morebi-directional communication links or signal lines 1898, 1818, 1815,1816, 1817, 1813, 1819, 1811, respectively.

The hub 1882 includes a power supply 1891 that provides power (e.g., DCpower supply) to a controller circuit 1884 via a connection 1885 (e.g.,communication link, signal line, electrical connection, etc.) andprovides power to RF circuitry 1890 via a connection 1887 (e.g.,communication link, signal line, electrical connection, etc.). Thecontroller circuit 1884 includes memory 1886 or is coupled to memorythat stores instructions which are executed by processing logic 1888(e.g., one or more processing units) of the controller circuit 1884 forcontrolling operations of the hub for forming and monitoring thewireless asymmetrical network as discussed herein. The RF circuitry 1890may include a transceiver or separate transmitter (TX) 1892 and receiver(RX) 1894 functionality for sending and receiving bi-directionalcommunications via antenna(s) 1896 with the wireless sensor nodes orother hubs. The RF circuitry 1890 communicates bi-directionally with thecontroller circuit 1884 via a connection 1889 (e.g., communication link,signal line, electrical connection, etc.). The hub 1882 can be awireless control device 1884 or the controller circuit 1884, RFcircuitry 1890, and antenna(s) 1896 in combination may form the wirelesscontrol device as discussed herein.

RF circuitry 1870 and antenna(s) 1871 of the system or RF circuitry 1890and antenna(s) 1896 of the hub 1882 are used to send and receiveinformation over a wireless link or network to one or more otherwireless devices of the hubs or sensors nodes discussed herein. Audiocircuitry 1860 is coupled to audio speaker 1862 and microphone 1064 andincludes known circuitry for processing voice signals. One or moreprocessing units 1814 communicate with one or more machine-accessiblenon-transitory mediums 1850 (e.g., computer-readable medium) viacontroller 1820. Medium 1850 can be any device or medium (e.g., storagedevice, storage medium) that can store code and/or data for use by oneor more processing units 1814. Medium 1850 can include a memoryhierarchy, including but not limited to cache, main memory and secondarymemory.

The medium 1850 or memory 1886 stores one or more sets of instructions(or software) embodying any one or more of the methodologies orfunctions described herein. The software may include an operating system1852, network services software 1856 for establishing, monitoring, andcontrolling wireless asymmetric network architectures, communicationsmodule 1854, and applications 1858 (e.g., home or building securityapplications, home or building integrity applications, developerapplications, etc.). The software may also reside, completely or atleast partially, within the medium 1850, memory 1886, processing logic1888, or within the processing units 1814 during execution thereof bythe device 1800. The components shown in FIG. 18 may be implemented inhardware, software, firmware or any combination thereof, including oneor more signal processing and/or application specific integratedcircuits.

Communication module 1854 enables communication with other devices. TheI/O unit 1830 communicates with different types of input/output (I/O)devices 1834 (e.g., a display, a liquid crystal display (LCD), a plasmadisplay, a cathode ray tube (CRT), touch display device, or touch screenfor receiving user input and displaying output, an optional alphanumericinput device).

In one embodiment, a system includes a hub having one or more processingunits and RF circuitry for transmitting and receiving communications ina wireless network architecture of a wireless network and a plurality ofsensor nodes each having a wireless device with transmitterfunctionality and receiver functionality to enable bi-directionalcommunications with the hub in the wireless network architecture. Theone or more processing units of the hub are configured to executeinstructions to cause a change from a first power mode of a receiver ofa sensor node to a second power mode upon transmitting notifications tothe sensor node during a repeated hub broadcasting time slot.

In one example, the notifications originate from the hub or from adifferent sensor node. The receiver functionality of the sensor node isconfigured at a minimum level of power to listen to broadcast messagesduring the first power mode and operable during the second power mode atany level above the minimum level of power including having operabletransmitter functionality.

In another example, the sensor node is configured to executeinstructions to determine a group identifier for the receivednotifications, to determine a group identifier for the sensor node, andto cancel transmission of a communication from the sensor node if thegroup identifier for the received notifications matches the groupidentifier for the sensor node to reduce congestion within the wirelessnetwork.

In another example, the sensor node is configured to executeinstructions to transmit a notification, to verify successful receptionof any notification of a group of nodes by checking a next hub broadcastslot for notice forwarding, and to retransmit the notification with atleast one modified parameter of a pseudo random function when successfulreception is not verified.

In another example, the one or more processing units of the hub areconfigured to execute instructions to determine transmission time slotsfor the plurality of sensor nodes using a pseudo random slot locationbased on sensor nodes in a group being less likely to have a same timeslot compared to other sensor nodes in the group while sensor nodes indifferent groups being more likely to occupy a same time slot.

In another example, the one or more processing units of the hub areconfigured to execute instructions to determine a first length of timeslots for notifications within the wireless network and a second lengthof time slots for data communications.

In the foregoing specification, the invention has been described withreference to specific exemplary embodiments thereof. It will, however,be evident that various modifications and changes may be made theretowithout departing from the broader spirit and scope of the invention.The specification and drawings are, accordingly, to be regarded in anillustrative rather than a restrictive sense.

What is claimed is:
 1. A system, comprising: a hub having one or moreprocessing units and RF circuitry for transmitting and receivingcommunications in a wireless network architecture of a wireless network;and a plurality of sensor nodes each having a wireless device withtransmitter functionality and receiver functionality to enablebi-directional communications with the hub in the wireless networkarchitecture, wherein the one or more processing units of the hub areconfigured to execute instructions to determine a first time length fora notification time slot for transmitting a notification including acontrol packet from a sensor node to the hub during the notificationtime slot and to determine a second different time length for a datatime slot for transmitting a data communication from the sensor node tothe hub during the data time slot.
 2. The system of claim 1, whereinnotifications originate from the hub or from a different sensor node. 3.The system of claim 2, wherein the receiver functionality of the sensornode is configured at a first level of power to listen to broadcastmessages while transmitter functionality is not operable during a firstpower mode and the receiver functionality is operable during a secondpower mode at a second level of power with operable transmitterfunctionality.
 4. The system of claim 3, wherein the sensor node isconfigured to execute instructions to determine a group identifier forthe received notifications, to determine a group identifier for thesensor node, and to avoid transmission of a communication from thesensor node if the group identifier for the received notificationsmatches the group identifier for the sensor node to reduce congestionwithin the wireless network.
 5. The system of claim 1, wherein thesensor node is configured to execute instructions to transmit anotification, to verify successful reception of any notification of agroup of nodes by checking a next hub broadcast slot for noticeforwarding, and to retransmit the notification with at least onemodified parameter of a pseudo random function when successful receptionis not verified.
 6. The system of claim 1, wherein the one or moreprocessing units of the hub are configured to execute instructions todetermine transmission time slots for the plurality of sensor nodesusing a pseudo random slot time allocation based on sensor nodes in agroup being less likely to have a same time slot compared to othersensor nodes in the group while sensor nodes in different groups beingmore likely to occupy a same time slot.
 7. The system of claim 1,wherein the first length of time slots for notifications is less than500 microseconds and the second length of time slots for datacommunications is at least 1 millisecond.
 8. An apparatus, comprising: amemory for storing instructions; one or more processing units to executeinstructions for monitoring a plurality of sensor nodes in a wirelessnetwork architecture; and radio frequency (RF) circuitry to transmitcommunications to and receive communications from the plurality ofsensor nodes each having a wireless device with a transmitter and areceiver to enable bi-directional communications with the RF circuitryof the apparatus in the wireless network architecture, wherein the oneor more processing units of the apparatus are configured to executeinstructions to receive a first communication with first alarminformation from a first group of sensor nodes, to receive a secondcommunication with second alarm information from a second group ofsensor nodes, to generate an aggregated alarm packet having the firstalarm information and the second alarm information, and to receive athird communication with the first alarm information from the firstgroup of sensor nodes when the first group of sensor nodes does notreceive the aggregated alarm packet from the apparatus.
 9. The apparatusof claim 8, wherein the one or more processing units of the apparatusare configured to execute instructions to identify unique alarms fromthe first alarm information and the second alarm information.
 10. Theapparatus of claim 9, wherein the one or more processing units of theapparatus are configured to execute instructions to transmit theaggregated alarm packet to the first and second group of sensor nodes.11. The apparatus of claim 10, wherein the first group of sensor nodesdoes not retransmit the first alarm information with the thirdcommunication when the first group of sensor nodes does receive theaggregated alarm packet from the apparatus.
 12. The apparatus of claim11, wherein the one or more processing units of the apparatus areconfigured to execute instructions to assign a downlink alarm time slotfor the aggregated alarm packet to be transmitted to the sensor nodes byusing a hash function.
 13. The apparatus of claim 12, wherein the one ormore processing units of the apparatus are configured to executeinstructions to cause a change from a first power mode of a receiver ofa sensor node to a second power mode upon transmitting the alarm packetwith the alarm information to the sensor node during a repeated hubbroadcasting time slot.
 14. A sensor node for a wireless networkarchitecture, comprising: at least one sensor; a memory for storinginstructions; processing logic coupled to the memory and the at leastone sensor, the processing logic to execute instructions for processingdata received from the at least one sensor and for processingcommunications for the sensor node; and radio frequency (RF) circuitrycoupled to the processing logic, the RF circuitry includes transmitterand receiver functionality to transmit communications to a hub and toreceive communications from the hub in the wireless networkarchitecture, wherein the processing logic of the sensor node isconfigured to receive information from the hub specifying a first timelength for a notification time slot for transmitting a notificationincluding a control packet from the sensor node to the hub during thenotification time slot and to determine a second different time lengthfor a data time slot for transmitting a data communication from thesensor node to the hub during the data time slot.
 15. The sensor node ofclaim 14, wherein the notifications include control, alarm, orforwarding packets that originate from the hub or from a group of sensornodes.
 16. The sensor node of claim 14, wherein the receiverfunctionality of the sensor node is configured at a first level of powerto listen to broadcast messages during a first power mode and operableduring a second power mode at a second level of power with operabletransmitter functionality.
 17. The sensor node of claim 14, wherein theprocessing logic is configured to execute instructions to determine agroup identifier for the received communications, to determine a groupidentifier for the sensor node, and to avoid transmission of acommunication from the sensor node if the group identifier for thereceived communications matches the group identifier for the sensor nodeto reduce congestion within the wireless network.
 18. The sensor node ofclaim 17, wherein a group of sensor nodes is formed to increase alikelihood that the group of sensor nodes will transmit communicationsat approximately the same time or close in time.
 19. The sensor node ofclaim 14, wherein the first length of time slots for notifications isless than 500 microseconds and the second length of time slots for datacommunications is at least 1 millisecond.
 20. The sensor node of claim14, wherein the processing logic is configured to execute instructionsto transmit a communication, to verify successful reception of anycommunication by checking a next hub broadcast slot for noticeforwarding, and to retransmit the communication with at least onemodified parameter of a pseudo random function when successful receptionis not verified.